|Lissan, an Aenar female (2154)|
The Aenar (pronounced EE-nar) were a humanoid race native to the Northern Wastes of Andoria, and a subspecies of the Andorians. Their population, during the mid-22nd century, consisted of only a few thousand.
The Aenar were physiologically very similar to the Andorians, which was reflected in their genome. Like Andorians, they had two antennae sprouting from their heads, although the antennae of the Aenar had small indentations in the funnel shaped tips. The Aenar were completely blind yet had the ability to "see", and all had no skin or hair pigment, resulting in a pale white appearance similar to Human albinos. The most distinctive trait of the Aenar, however, were their highly evolved telepathic abilities. An Aenar was capable of reading minds and of psychically projecting itself to other humanoids. They used telepathy to communicate amongst themselves. They were genetically compatible with Andorians; Aenar Jhamel and Andorian Shran had a child, Talla. A hybrid Aenar/Andorian individual, such as Talla, had a greenish skin tone.
The Aenar of the 22nd century lived in an underground compound on Andoria, shielded by a dampening field. The Aenar had no leader, but would appoint a de facto leader, or speaker, if a situation warranted it. Aenar had a strict law against reading the minds of other people without prior consent. They had a strictly pacifist ideology, and deplore violence.
The Aenar were considered a myth in Andorian society for a long time. But in 2104, the Andorians rediscovered the Aenar living in the Northern Wastes of Andoria. After that, they maintained diplomatic contact with the Andorian government, though they remained extremely secretive. Shran claimed he could count on one hand the number of Andorians who had seen one face to face.
In 2154, the Aenar became involved in interstellar affairs when one individual, Gareb, was kidnapped by the Romulan Star Empire. Using telepresence, the Romulans used Gareb to remotely pilot an experimental drone ship.
It was not specified that the Aenar became members of the Federation as the Andorians had done, although this seems nearly certain given that they live on the same moon -- and it was noted in TNG: "Attached" that it had never been possible for a planet to join the UFP unless all sentient populations present agreed.
In TAS: "Yesteryear", Spock's replacement aboard the USS Enterprise in an alternate timeline was an Andorian named Thelin, who had pale colored skin similar to the Aenar. Of course, this was an animation error (one of the producers was colorblind; the TAS: "Yesteryear" script did specify that Thelin was to have blue skin). Retroactively speaking, it is possible to extrapolate that Thelin was of Aenar descent. Of course, since Mr. Spock was able to correct the timeline, it is also possible that Thelin never existed in the restored timeline.
In the Star Trek: Myriad Universes story The Chimes at Midnight, which explores the timeline from "Yesteryear", Thelin is confirmed to have an Aenar parent.